1. Field of the Invention
The present invention relates to a double bag for application of a fluid substance, in particular a nutrient solution, and including an outer bag having at least two adjoining each other edges, and an inner bag containing the fluid substance and located in the outer bag, with the fluid substance flowing, at least partially, into the outer bag upon opening of the inner bag.
2. Description of the Prior Art
A double bag of the above-described type is disclosed, e.g., in German application 196 00 530.2. These double bags are particularly used for storage and administering of prepared nutrient solutions. The solutions are administered to patients, e.g., with so-called sonde systems. With these systems, a conventional intake of food after an operative connection is not possible.
The nutrient solutions usually contain substances necessary for supporting life such as proteins, fats, carbohydrates, minerals, vitamins, and micronutrients.
Originally the containers for storing and administering of the nutrient solutions were made of glass. However, glass containers have serious drawback, it is difficult to transport them, they require much space for their storage, and they are difficult to handle during use. Another very serious drawback of the glass containers consists in that during administering of a solution, air is sucked in. This presents a risk of germs penetrating into the nutrient solution, which is dangerous to the patient.
The foregoing drawbacks were substantially eliminated with the development of plastic containers for the nutrient solutions. In order to protect them from the influence of light, oxygen, sun, temperature fluctuations, ets . . . , the solutions are stored in the inner, opaque and air--tight bag, which is placed into the outer bag, and the solution flows from the inner bag into the outer bag upon opening of the inner bag. The outer bag is preferably at least partially transparent so that the condition of the nutrient solution can be checked before use.
Plastic or foil containers or bags better protect the solutions from the environmental influence then conventional glass containers. Upon discharge of the container or the bag, no space remains which can be filled by air, rather the size of a bag is reduced with the fluid substance having been discharge.
However, the above-described double bag containers have a serious drawback which consists in that the bags at least partially impede the flow of the fluid substance. E.g., an adhesion between bag walls can take place. The adhesion can completely block the flow of the fluid substance from the inner bag into the outer bag and the discharge from the outer bag. Another drawback of a double bag consists in that often a substantial amount of the fluid substance remains in the bags, and its a practically complete discharge is not possible.
Accordingly, an object of the present invention is a double bag of the above-described type which would provide for an improved discharge of a fluid substance.